Barrel-aging is just shy of commonplace now, with bourbon barrels, wine barrels and (increasingly) gin barrels playing host to beers for months at a time, adding booze and wood and all kinds of other delightful flavors. Mezcal barrels are new territory for barrel-aging, but in the hands of Firestone Walker brewmaster (and secret wizard) Matt Brynildson, good things are sure to happen.

“Mezcal is one of the best ways to incorporate smoke flavors into a beer,” Brynildson says. “It blew my mind when the barrel showed up. I thought there might be a touch of smoke but holy cow.”

In case it’s been awhile since your last ragingly awful Cancun hangover, mezcal is an agave-based spirit similar to tequila, but it’s made from roasted piña (the heart of an agave plant), which lends that smoky flavor. Brynildson worked with Yard House Restaurants and Chicago-based One Off Hospitality Group (The Publican, Big Star) to craft two limited edition mezcal barrel-aged beers. The first is called Traveling Oak, a Del Maguey mezcal barrel-aged verison of Parabola, Firestone’s Russian imperial stout, and it debuts April 7 at Yard House locations in Long Beach, San Jose, Boston, Denver and Seattle. Portland gets its chance to try the beer at Yard House on April 14. The second is Viaje de Roble, a Fidencio mezcal barrel-aged stock ale (a traditionally sweet, malt-forward brew with fruity esters) to debut at a dinner at Big Star tonight and stay on tap there and at The Publican for as long as kegs last.

The barrels used for both beers have long histories. The barrels used to craft Traveling Oak began life as Old Rip Van Winkle bourbon vessels before heading to Del Maguey, where they aged a bourbon barrel mezcal. Only then were they ready to make their long journey to Firestone Walker, where Brynildson filled them with Parabola.

“Parabola stout is full of roasty and smokey flavors,” Brynildson says. “Aging for about a year trimmed off some jagged and rough edges from the beer and allowed what was in the barrel to come through. You get this mezcal smokey character and some of the vanilla and oak, and there still is this touch of tequila, a touch of agave type spirit character in there.”

The Publican/Big Star beer, Viaje de Roble, has a story that begins with a W.L. Weller Antique 107 bourbon barrel. That barrel then headed to Oaxaca, Mexico, where it rested for 70 days with a Fidencio mezcal inside. Once Big Star’s beverage director Laurent Lebec had a chance to sample the mezcal, he knew the barrel had more to give. On the last leg of its journey, the barrel headed to Paso Robles, ready for Firestone Walker’s beer.

So, are Mexican and South American spirits the new bourbon when it comes to barrel aging? Brynildson is certainly on board. “Let’s go south of the border to look at cachaca and all these other spirits that are barrel-aged. That’s at the cutting edge of what you’ll see more of coming down the pipes.”